Gesture recognition, especially hand gesture recognition enables humans to interface with the machine and interact naturally without any mechanical devices. The gesture recognition can be conducted with techniques from computer vision and image processing. Using the concept of gesture recognition, it is possible to point a finger at the computer screen so that the cursor will move accordingly. The gesture includes static gesture, e.g. a victory sign (a hand gesture in which the index finger and middle finger are extended and parted whilst the thumb and remaining fingers are clenched), and dynamic gesture, i.e. within a period of a single valid gesture input, the shape (e.g. extend some fingers or clench some fingers) and/or position of user's hand is changed so as to form a valid gesture input. And sometimes, a consecutive hand shape change and/or hand movement can be interpreted as two or more instructions for the device.
The gesture input is applied into many fields. One application of the hand gesture input is a book reading application. For example, upon a horizontal stroke of a user hand (the trajectory of hand movement is substantially horizontal and the movement distance exceeds a certain value, e.g. 15 centimeters) before a camera, the device interprets this gesture input as an instruction to flip a page of the book. The backward or forward flip of the book depends on the movement orientation. FIG. 1 is a diagram illustrating a rightward gesture signaling the backward flip of the book according to the prior art. As can be seen from the FIG. 1, in order to make the rightward gesture, a user has to firstly put his right hand in front of the camera, and then move rightward for a certain distance. When the gesture is complete, i.e. the hand arrives at the stop position as FIG. 1 shows; the user needs to quickly withdraw his hand before the camera. Considering a scenario that user wants to flip several pages, let's say 5 pages at a time, he needs to perform 5 times of raising his hand, moving, stopping and withdrawing. It's really inconvenient for user and therefore reduces the user experience.
It's desired a new way of consecutive gesture inputs.